var  xmlhttp;

function SendUpdateMessages(url){
try {
		xmlhttp = new XMLHttpRequest();
	}
	catch (e) {
		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
			//alert(xmlhttp);
			//当方法为post时需要如下设置http头
			//xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
			//xmlhttp.setRequestHeader("If-Modified-Since","0");
			//xmlhttp.setRequestHeader("Cache-Control","no-cache");
			//打开连接，true表示异步提交
	xmlhttp.open("get", url, true);
	xmlhttp.send(null);
	xmlhttp.onreadystatechange = callBackFunction;
}
function callBackFunction() {
	if (4 == xmlhttp.readyState) {
		if (200 == xmlhttp.status) {
			var data = xmlhttp.responseText;
			var message = document.getElementById("operateMessage");
			message.innerHTML = "<font color='red'>(" + data + ")</font>";
		} else {
			alert("error");
		}
	}
}